A new San Francisco law goes into effect on Thursday that prevents fast-food restaurants from giving away trinkets, action figures and other toys in their kid's meals unless their food meets nutritional requirements.

Parents who order Happy Meals at the 19 McDonald's locations in San Francisco will have to request the toy and pay 10 cents. That amount will be donated to the Ronald McDonald House of San Francisco. Burger King, which has 13 restaurants in San Francisco, announced that it will also offer kids meals' toys for 10 cents.

McDonald's kid's meals do not meet the law's nutritional standards. The meals have to be less than 600 calories and contain fruits (a half-cup) and vegetables (3/4 of a cup). They must have less than 35% of the total calories coming from fat, less than 640 milligrams of sodium and less than 0.5 milligrams of trans fat.

The current Happy Meal consisting of a hamburger, kid's-size fries and a cola would meet the calorie, calories from fat, sodium and trans fat requirements under the San Francisco law. It would contain 500 calories, 125 calories from fat and 600 milligrams of sodium.

But it would not meet the fruit and vegetable quota. The pickle and onion on the hamburger does not come near the required ¾ cup of vegetables. The French fries do not count as a vegetable, according to the San Francisco Department of Public Health.

The new law will affect about 50 fast-food restaurants in San Francisco such as Burger King, Carl's Jr. and Subway.

"Our efforts are geared towards addressing childhood obesity epidemic," said San Francisco City and County Supervisor Eric Mar, who proposed the ordinance.

About one-third of children in the United States are either overweight or obese, according to data compiled by the Centers for Disease Control and Prevention. Health advocates have long accused fast-food restaurants of enticing children to eat fast-food meals high in fat and sodium by using toys tied to characters in new movies.

McDonald's said in a statement: "While we will fully comply with this law, we also have a responsibility to give our customers what they want.

"Parents have told us they'd still like the option of purchasing a toy separately for their child when they buy them a Happy Meal or Mighty Kids Meal."

The announcement that the money from toys would go to charity was met by skepticism by Corporate Accountability International, a corporate watchdog group.

"As McDonald's long has, it is again using a charity that helps children get well to defend a practice that contributes to a range of diet-related conditions like diabetes. Currently McDonald's uses its contributions to the charity to defend the hundreds of millions it spends marketing its junk food brand to kids each year," according to the group's statement.

The new ordinance has had a greater impact beyond San Francisco, Mar said.

"We inspired other local cities, parent activists and health organizers to take up the issue too," he said. "We started a national dialogue in San Francisco. It has become a national issue."

Mar said he met with several franchise owners in the city regarding the ordinance. Despite initial opposition to the law last year, he said that there's growing awareness that having healthy options is good business practice.

Earlier this year, hamburger chain Jack-in-the-Box announced it would discontinue kids' toys in their meals for children.

The meals will carry apple slices, reduced portion of French fries and a choice of beverage, including new fat-free chocolate milk and 1% low-fat white milk, instead of defaulting to soda. The changes started in September and will spread nationwide by the end of March 2012.

However, the new version of the Happy Meal still does not meet the requirements of the San Francisco law.

Although the San Francisco law has been criticized as legislating health and nutrition, Mar said the responsibility ultimately falls on the parents. But, fast-food restaurants play a role and "benefit from the pester power of the kids of young ages," he said.

"It's our job as a local legislator to protect public health," he said. "Nothing is more important than children's health."

He said the momentum for this law came from pediatricians and mainly parents who live in the lowest income neighborhoods. "They were the main voices of our campaign," he said.